Evaluation of the effects of oceanic acidification on the photosynthesis of Ulva lactuca

• Grant number: 22/06468-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2022
• End date: March 31, 2023
• Field of knowledge: Biological Sciences - Botany - Pant Physiology
• Principal Investigator: Milton Costa Lima Neto
• Grantee: Letícia Viana Barboza
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil

Abstract

With industrialization, there has been an increase in the emission of carbon dioxide gas, which has caused several problems, from questions about climate change to ocean acidification. Ocean acidification is caused, as the oceans act as a carbon sink, absorbing a considerable portion of atmospheric CO2. However, this uptake causes a decrease in pH and an increase in ocean acidity, since when CO2 is absorbed by the ocean it reacts with water, triggering a series of reversible chemical reactions that result in the release of hydrogen ions (H+) in this medium. Thus, as a result of this change in pH, there are several impacts on marine organisms, influencing their physiology, carbon fixation and their calcification rate. In addition, considering that in coastal regions ocean acidification can also be caused by other factors, it is essential to carry out studies on the possible impacts of this change on coastal organisms, especially in relation to marine algae and photosynthesis. From this, the present study will use the species Ulva lactuca, considering the numerous characteristics of this important macroalgae, such as: wide distribution, abundance, economic importance, ability to survive in different salinities, rapid growth and potential use as a bioindicator for several environmental parameters. In this way, we intend to evaluate both the photosynthetic effects resulting from the exposure of U. lactuca to two different pH values, as well as to analyze its potential use as a bioindicator of pH decrease. For this will be analyzed: chlorophyll a fluorescence kinetics, growth and productivity parameters, and chlorophyll and carotenoid contents. (AU)